• Title/Summary/Keyword: D 002

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Numerical simulation of 2-D fluid-structure interaction with a tightly coupled solver and establishment of the mooring model

  • Tsai, I-Chen;Li, Sing-Ya;Hsiao, Shih-Chun;Hsiao, Yu
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.433-449
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    • 2021
  • In this study, a newly enhanced Fluid-Structure Interaction (FSI) model which incorporates mooring lines was used to simulate a floating structure. The model has two parts: a Computational Fluid Dynamics (CFD) model and a mooring model. The open-source CFD OpenFOAM® v1712 toolbox was used in the present study, and the convergence criteria and relaxation method were added to the computational procedure used for the OpenFOAM multiphase flow solver, interDyMFoam. A newly enhanced, tightly coupled solver, CoupledinterDyMFoam, was used to decrease the artificial added mass effect, and the results were validated through a series of benchmark cases. The mooring model, based on the finite element method, was established in MATLAB® and was validated against a benchmark analytical elastic catenary solution and numerical results. Finally, a model which simulates a floating structure with mooring lines was successfully constructed by connecting the mooring model to CoupledinterDyMFoam.

Numerical investigation on the wave interferences of submerged bodies operating near the free surface

  • Li, Dong;Yang, Qun;Zhai, Lin;Wang, Zhen;He, Chuan-lin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.65-74
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    • 2021
  • A key factor that governs the wave interferences of a submerged body is the dimensionless Froude number. Computational Fluid Dynamics (CFD) is used to describe the resistance force coefficients and the generated waves of two SUBOFF submarine models. Grid independence studies are performed on two cases, totally and shallowly submerged cases, with four sets of computing meshes. The highest peaks are marked by red points at given wavelengths, a line is fitted to those points with a least-squares approximation, and the half wake angle at multiple Froude numbers is defined between the fitted line and the centerline of the free surface. The results show that when the depth of the target is 1.1D, constructive interferences occur at Fn = 0.3 and 0.5, while destructive interference occurs at Fn = 0.35 with distortion of the waveform. The half wake angle is less than 19.47° because of the interference between the bow and stern wave systems.

Mission planning and performance verification of an unmanned surface vehicle using a genetic algorithm

  • Park, Jihoon;Kim, Sukkeun;Noh, Geemoon;Kim, Hyeongmin;Lee, Daewoo;Lee, Inwon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.575-584
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    • 2021
  • This study contains the process of developing a Mission Planning System (MPS) of an USV that can be applied in real situations and verifying them through HILS. In this study, we set the scenario of a single USV with limited operating time. Since the USV may not perform some missions due to the limited operating time, an objective function was defined to maximize the Mission Achievement Rate (MAR). We used a genetic algorithm to solve the problem model, and proposed a method using a 3-D population. The simulation showed that the probability of deriving the global optimal solution of the mission planning algorithm was 96.6% and the computation time was 1.6 s. Furthermore, USV showed it performs the mission according to the results of the MPS. We expect that the MPS developed in this study can be applied to the real environment where USV performs missions with limited time conditions.

Effects of Gargle Using Natural Substances on Oral Environment

  • Kyung Min Kim;Kyung Yae Hyun;Min Kyung Lee
    • Biomedical Science Letters
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    • v.29 no.2
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    • pp.75-80
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    • 2023
  • In this study, natural mouthwash was developed based on natural substances based on cinnamon and ginger, which are familiar to the public, to check the effectiveness of mouthwash and changes in microbial distribution. This study was conducted on 24 people who fully explained the purpose and method of the study and agreed to participate among those who visited D University from October 2021 to December 2021. The subject's oral cavity was examined and placed in three groups to have similar conditions, and after using mouthwash for a week, a survey, saliva test, breath measurement test, and PCR test were performed. As a result of the experiment, the amount of saliva after using natural mouthwash increased compared to the control group (P<0.05). In the comparison of bacteria, it was confirmed that Pg and Fn bacteria decreased after using natural mouthwash (Pg t=4.852, P=.002, Fn t=2.888, P=.023). Following this study, it is expected that research on the development and efficacy of natural mouthwash will be conducted through various clinical applications, which will be useful in real life and dental care institutions.

말기암 환자 가족에 대한 호스피스 팀의 정보적 지지 제공 효과

  • Lee, Hye-Won
    • Korean Journal of Hospice Care
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    • v.1 no.1
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    • pp.34-45
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    • 2001
  • To evaluate the effect of informational support by hospice team on family caregivers of terminally ill cancer patients, 22 family caregivers of D University Hospital in Daegu city were participated. The research was conducted from Aug. 16th to Oct. 28th 2000 by using self-reported questionnaires. The instruments used in this study were the Weinert's scale of perceived social support, Spielberger's state anxiety inventory, CES-D, and Ellison and Paloutzian's spiritual well-being scale. The intervention was designed to give educational and counselling program up to 7 times within 4 weeks. Educational and counselling booklets which made by the researcher were used step by step by hospice team. The data were analysed frequency, percentage, Wilcoxon Singed Ranks Test Test with SPSS Win 10.0/PC. The results obtained from this study were as follows: 1.The perceived social support of family caregivers was significantly increased after ready planned informational support was applied by hospice team(z=-3.045, p=0.002). 2.The anxiety of family caregivers was significantly reduced after ready planned informational support was applied by hospice team(z=-3.348, p=0.001). 3.The depression of family caregivers was significantly reduced after ready planned informational support was applied by hospice team(z=-3.641, p=0.000). 4.The spiritual well-being score of family caregivers was not significantly improved after ready planned informational support was applied by hospice team(z=-0.422, p=0.673). In conclusion, the results of this study clearly suggests that the informational support provided by hospice team not only increased the family caregivers' who are caring for terminally ill cancer patients. Therefor the informational support program designed by researcher for family caregivers who are caring for terminally ill cancer patients should be utilized and expended.

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Korean Red Ginseng enhances cardiac hemodynamics on doxorubicin-induced toxicity in rats

  • Jang, Young-Jin;Lee, Dongbin;Hossain, Mohammad Amjad;Aravinthan, Adithan;Kang, Chang-Won;Kim, Nam Soo;Kim, Jong-Hoon
    • Journal of Ginseng Research
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    • v.44 no.3
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    • pp.483-489
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    • 2020
  • Background: Korean Red Ginseng (KRG) has been known to possess many ginsenosides. These ginsenosides are used for curing cardiovascular problems. The present study show the protective potential of KRG against doxorubicin (DOX)-induced myocardial dysfunction, by assessing electrocardiographic, hemodynamic, and biochemical parameters and histopathological findings. Methods: Animals were fed a standard chow and adjusted to their environment for 3 days before the experiments. Next, the rats were equally divided into five groups (n = 9, each group). The animals were administered with KRG (250 and 500 mg/kg) for 10 days and injected with DOX (20 mg/kg, subcutaneously, twice at a 24-h interval) on the 8th and 9th day. Electrocardiography and echocardiography were performed to study hemodynamics. Plasma levels of superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde were measured. In addition, the dose of troponin I and activity of myeloperoxidase in serum and cardiac tissue were analyzed, and the histopathological findings were evaluated using light microscopy. Results: Administration of KRG at a dose of 250 and 500 mg/kg recovered electrocardiographic changes, ejection fraction, fractional shortening, left ventricular systolic pressure, the maximal rate of change in left ventricle contraction (-dP/dtmax), and left ventricle relaxation (-dP/dtmax). In addition, KRG treatment significantly normalized the oxidative stress markers in plasma, dose dependently. In addition, the values of troponin I and myeloperoxidase were ameliorated by KRG treatment, dose dependently. And, KRG treatment showed better histopathological findings when compared with the DOX control group. Conclusion: These mean that KRG mitigates myocardial damage by modulating the hemodynamics, histopathological abnormality, and oxidative stress related to DOX-induced cardiomyopathy in rats. The results of the present study show protective effects of KRG on cardiac toxicity.

Effects of Active Mandibular Exercise for Mouth Opening Limitation Patients after Maxillomandibular Fixation Release: A Non-Randomized Controlled Trial (악간고정 제거후 개구장애 환자에게 적용한 능동적 하악운동의 효과: 비무작위 대조군 설계)

  • Jang, Hyo Jin;Kim, Myung Hee
    • Journal of Korean Academy of Nursing
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    • v.48 no.1
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    • pp.26-37
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    • 2018
  • Purpose: The aim of this study was to evaluate the effects of active mandibular exercise (AME) in patients with limited mouth opening after maxillomandibular fixation (MMF) release. Methods: The study used a quasi-experimental, nonequivalent control group and a pre test-post test design. Sixty-two patients with Maxillomandibular Fixation Release were assigned to the experimental (n=31) or control group (n=31). The AME was performed in the experimental group for 4 weeks. The exercise AME consisted of maximal mouth opening, lateral excursion and protrusive movement. These movements were repeated ten times a day. After the final exercise of the day, the number of tongue blades used for mouth opening was noted. The effect of AME was evaluated after MMF release at different time intervals: a) immediately, b) after 1 week, c) after 2 weeks, d) after 4 weeks, and e) after 12 weeks. The exercise was assessed using the following criteria: a) mandibular movements, b) pain scores associated with maximal mouth opening, c) discomfort scores associated with range of movement, and d) daily life activities that involve opening the mouth. Results: The experimental group showed significant improvement regarding the range of mandibular movements (maximal mouth opening (F=23.60, p<.001), lateral excursion to the right side (F=5.25, p=.002), lateral excursion to the left side (F=5.97, p=.001), protrusive movement (F=5.51, p=.001)), pain score (F=39.59, p<.001), discomfort score (F=9.38, p<.001). Daily life activities that involve opening the mouth were more favorable compared to those in the control group. Conclusion: The AME in patients after MMF release is helpful for increasing mandibular movement range, decreasing pain and discomfort, and improving day life activities that involve opening the mouth. Therefore, AME is highly recommended as an effective nursing intervention.

Cephalometric Angular Measurements of the Mandible Using Three-Dimensional Computed Tomography Scans in Koreans

  • Kim, Yong Hyun;Kang, Seok Joo;Sun, Hook
    • Archives of Plastic Surgery
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    • v.43 no.1
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    • pp.32-37
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    • 2016
  • Background We conducted this study to analyze the values of the key cephalometric angular measurements of the mandible using 3-dimensional (3D) computed tomography scans. Methods In the 106 enrolled patients, a 3D cephalometric analysis was performed to measure the angular variables of the mandible. These values were compared between the two sides and between the two sexes. Results The frontal measurements revealed that the mandibular body curve angle was larger on the left (Lt) side (right [Rt], $141.24{\pm}7.54$; Lt, $142.68{\pm}6.94$; P=0.002) and the gonial angle was larger on the right side (Rt, $134.37{\pm}8.44$; Lt, $131.54{\pm}7.14$; P<0.001). The sagittal measurements showed that the gonial angle was larger on the right side (Rt, $134.37{\pm}8.44$; Lt, $131.54{\pm}7.14$; P>0.05). Further, the transverse measurements revealed that the mandibular body curve angle was larger on the right side (Rt, $140.28{\pm}7.05$; Lt, $137.56{\pm}6.23$; P<0.001). Conclusions These results provide an average of the mandibular angular measurements for the Korean population, establishing a standard for determining surgical patient groups and outcome evaluations in the field of mandible contour surgery.

Influence of Sunflower Whole Seeds or Oil on Ruminal Fermentation, Milk Production, Composition, and Fatty Acid Profile in Lactating Goats

  • Morsy, T.A.;Kholif, S.M.;Kholif, A.E.;Matloup, O.H.;Salem, A.Z.M.;Elella, A. Abu
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.8
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    • pp.1116-1122
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    • 2015
  • This study aimed to investigate the effect of sunflower seeds, either as whole or as oil, on rumen fermentation, milk production, milk composition and fatty acids profile in dairy goats. Fifteen lactating Damascus goats were divided randomly into three groups (n = 5) fed a basal diet of concentrate feed mixture and fresh Trifolium alexandrinum at 50:50 on dry matter basis (Control) in addition to 50 g/head/d sunflower seeds whole (SS) or 20 mL/head/d sunflower seeds oil (SO) in a complete randomized design. Milk was sampled every two weeks during 90 days of experimental period for chemical analysis and rumen was sampled at 30, 60, and 90 days of the experiment for ruminal pH, volatile fatty acids (tVFA), and ammonia-N determination. Addition of SO decreased (p = 0.017) ruminal pH, whereas SO and SS increased tVFA (p<0.001) and acetate (p = 0.034) concentrations. Serum glucose increased (p = 0.013) in SO and SS goats vs Control. The SO and SS treated goats had improved milk yield (p = 0.007) and milk fat content (p = 0.002). Moreover, SO increased milk lactose content (p = 0.048) and feed efficiency (p = 0.046) compared to Control. Both of SS and SO increased (p<0.05) milk unsaturated fatty acids content specially conjugated linolenic acid (CLA) vs Control. Addition of SS and SO increased (p = 0. 021) C18:3N3 fatty acid compared to Control diet. Data suggested that addition of either SS or SO to lactating goats ration had beneficial effects on milk yield and milk composition with enhancing milk content of healthy fatty acids (CLA and omega 3), without detrimental effects on animal performance.

Hypofractionated radiotherapy for early glottic cancer: a retrospective interim analysis of a single institution

  • Lee, Jeong Won;Lee, Jeong Eun;Park, Junhee;Sohn, Jin Ho;Ahn, Dongbin
    • Radiation Oncology Journal
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    • v.37 no.2
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    • pp.82-90
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    • 2019
  • Purpose: To evaluate the results of hypofractionated radiotherapy (HFX) for early glottic cancer. Materials and Methods: Eighty-five patients with cT1-2N0M0 squamous cell carcinoma of the glottis who had undergone HFX, performed using intensity-modulated radiotherapy (IMRT, n = 66) and three-dimensional conformal radiotherapy (3D CRT, n = 19) were analyzed. For all patients, radiotherapy was administered at 60.75 Gy in 27 fractions. Forty-three patients received a simultaneous integrated boost (SIB) of 2.3-2.5 Gy per tumor fraction. Results: The median follow-up duration was 29.9 months (range, 5.5 to 76.5 months). All patients achieved complete remission at a median of 50 days after the end of radiotherapy (range, 14 to 206 days). The 5-year rates for locoregional recurrence-free survival was 88.1%, and the 5-year overall survival rate was 86.2%. T2 stage was a prognostic factor for locoregional recurrence-free survival after radiotherapy (p = 0.002). SIB for the tumor did not affect disease control and survival (p = 0.191 and p = 0.387, respectively). No patients experienced acute or chronic toxicities of ≥grade 3. IMRT significantly decreased the dose administered to the carotid artery as opposed to 3D CRT (V35, p < 0.001; V50, p < 0.001). Conclusions: Patients treated with HFX achieved acceptable locoregional disease control rates and overall survival rates compared with previous HFX studies. A fraction size of 2.25 Gy provided good disease control regardless of SIB administration.